Improvement in machines for bending tubing



Z Sheets-Sheet 1. R.WRIGH1 MACHINE FOR BENDING TUBING.

Patented March 7,1876.

Z Sheets-Sheet 2. R. WRIGHT. MACHINE FOR BENDING TUBING.

171219112011 MM WWW 1m 2.3. mmbvn/ Patented March 7,1876.

WEEfiE#EW EEEEIE MPEFERS, PNOTD-LITMOGRAPHER, WASHINGTON, D O

ent length.

,port the pipe in UNI ED STATES ROBERT WRIGHT, 0F PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT m MACHINES 'FORBENDIING TUBING.

Specification forming part of Letters Patent No. 174,607, dated March 7, 1876; application filed January 7, 1576. i

"To all u'hom t'tma-y concern Be it known! that 1, ROBERT WR1GH'1,0f the city of Philadelphia and State of Pennsylvania, have invented certainnew and useful Improvements in Bending Metallic Pipes orTubes; and do I hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, making a part of this specification, in which- Figure 1 represents a perspective View of a machine used to subject the pipe to a longitudinal strain while being bent. Fig. 2 represents a transverse vertical section ofthe same, and also a transverse section of pipes and their packings. Fig. 3represen ts,'in perspective, a piece of square i e partially in section,

showing the packing formed of a series of held in position by thin, flat spring-plates, wedges formed of fiat spring-plates of differto inclose them, the whole being connected by rivets or screws. Fig.5 represents, in plan view, the under side of the machine, shown in Fig. 1, with pieces of pipes attached to it, and the packing employed in bending the pipes. Figs. '6, 7, 8, 9, and 10 represent more clearly and in detail the forms of pack bolts and nuts d, by which the friction proing shown-in Fig. 5.

In bending gas and other pipes, the metal on the inner curve is ordinarily compressed and liable to crimp or bend and thus reduce the original sectional area of the pipe. The object of my invention is to. completely supits interior, so that while being bent it shall retain its original sectional form; and my invention relates to a machine for clamping and holding the pipe, while being bent, so as to produce a longitudinal strain upon it and reduce the tendency to crimping on the inner curve or bend.

My invention further relates to an elastic metallic support placed within the pipe that is to be bent, said support being composed of a thin, flat steel ribbon wound spirally, and inclosing a strong mandrel made ofround wire, also wound spirally, the cross-section of the mandrel and steel-ribbon sleeve being Fig. 4 represents, in perspective, one of the wedgesformed of flat'spring-plates of difl'erent lengths, and a bent spring-plate round, square, or of any other form similar to the pipe that is to be bent.

- My invention further relates to an elastic metallic support placed outside of the pipe that is to be bent, said support being composed of a thin, flat, steel ribbon wound spirally and inclosed in a strong sleeve made of round wire, also wound spirally, the crosssection of the strong sleeve and steel ribbon being round, square, or'of any other form suitable to the pipethat is to be bent.

In the drawings,'A represents the bed-plate of the machine used to produce alongitudinal strain on the'pipeB, that is to be ;bent to a curve corresponding with the former G. This former is a short cylinder, having a circularorother shaped groove on its periphery for the reception of the pipe, into which it is kept .by the clamp wbolted to the cylinder O.-This= cylinder is :mounted upon a shaft revolving into suitable bearings 12 attached to-the bedplate A, and on'the shaft a head, 0, is formed, .so'as-to be revolved by means of levers or otherwise. Tothe top of the bed-plate A are attached two guide-plates D and-D, to direct the sliding clamp E, to which one end of the pipe B is attached by the clamping-plate and bolts 6. The guide-plate D is fastened permanently to the bed-plate A, but'the guide-plate .D is'connected to the bed-plate by means of duced by the guide-plates on theslidingclamp E can be regulated; the latter being dovetailed or beveled on the side next to the guide-plate the said plate can, by means of the nuts (I, be brought very tightly against the. side of the sliding clamp and produce much friction, thus exerting a great longitudinal strain upon the pipe B during the operation of bending around the form or cylinder 0, and thus preventing the pipe from crimping on the inner curve.- Y

In Fig. 5 is shown,at F, a piece of round pipe, with a portion represented as broken away to show the thin steel ribbon G wound spirally in the interior, thus forming asleeve F from abrasion by comto preserve the pipe ing into contact with the strong spring-mandrel H, made of round steel wire, fitting into the interior of the sleeve G. A similar pro- PATENT Orrron tection may he applied to the outside of the pipe F by placing a thin steel-ribbon sleeve And in Fig. 10, or at F, Fig. 5, a similar thinsteel ribbon G and spring-mandrel H are shown so formed as to be readily applied to the bending of pipes the cross-section of which is a square.

In Fig. 5 is shown,at I, a piece of square pipe, with a portion represented as broken away so asto exhibit the strong mandrel H in the center, bearing on one side against a series of links,'K, strung upon a flexible wire, and shown moreclearly in Fig. 6, while on the opposite side the mandrel H is bearing against a series of links, L, attached to two flexible strips by means of rivets, as shown also in Fig. 7. The same links K and L can be used in bending pipes of different sizes, as they .arecapable of expansion .or. contraction, as seen in Fig. 7, at the same time forming a flexible protection against injury to the walls of the pipe by the round spiral mandrel H.

In Fig. 3 is shown, at M, a piece of square pipe, with a portion represented as broken away to exhibit the internal packing, formed of a series of thin, flat springplates, N, retained together by a rivet, n, and two wedges P P to press the plates N against one of the wallsof the pipe M. Said wedges P P are' also composed of thin and flexible plates of difl'erent length, connected together'by a rivet, p, and inclosed by a thin plate folded over, so as to remove the inequalities or steps produced byjthe difl'erent lengths of-the thin plates forming each wedge.

In Fig. 5 is shown,at Q, a piece of round pipe partially in section, and also in Fig. 8, so as to exhibit the transverse plates R that fill the interior ofthe pipe. These plates are retained in position by beiu g strung upon'wire ropes q, and between each of them there is anelastic washer, r, of indie-rubber, or other elastic'substance, to allow the mandrel R't'o assume the requisite curve. Each plate B represents the'halfof a disk, and the two se ries of plates are forced apart by the wedge- 8, formed out of thin plates, as previously described, and support the pipe while it is bent.

At T, Fig. 5, a similarly-constructed mandrel is applied into the interior of a square pipe, U, with the wedge'S applied on one side of the mandrel, each plate being then made square,

as shown in side view, and also in section in Fig. 9, and in either case, after'bending the pipe, the mandrelcan readily be removed by first withdrawing the wedge S. e

I am aware thata flexible mandrel, consistiug'of a spiral coil of wire with aflattened exterior surface, is not new, and I K also aware that a flexible mandrel, consist! g ofa spiral coil of round wire with flexibleplatesruuning' lengthwise of the pipe, between the spiral coil and the pipe, has been used before, but this mode cannot be used in bending round pipes, and I do not claim either of these devices.

What I claim is-- 1. In a machine for bending pipes, the application of a longitudinal strain upon I the pipe during the operation of bending. .by

means of the cylinder'or former U and clamp a, in combination with th'eslidiug clamp E and guide-plates D and D, arranged substantially as shown and described. f

2. Incombination with a strong ma'nd rel, H, made of round wire wound spirally, the thin, flat steel ribbon wound spirally upon the man drel H, and between it and the pipe that is to be bent, to protect the latter from abrasion, substantially as described and represented.

3. In combination with a strong sleeve, H, I

made of round wire wound spirally, the thin, flat steel ribbon wound spirally within the sleeve H, and between itand the pipe that is to be bent, to protect the latter from abrasion, substantially as described. y 4

t ROBERT WRIGHT.

Witnesses: y

J. PLANKINION,

H. H. GREENMAN. 

